so long story short i was trying to make an old x86 laptop boot into a live cd environment i could use, but i didnt have a livecd so i used debian’s install cd, but i wanted to try out guix
When i copied files off the guix cd the kernel would spew errors (earlier oops). debian 12.
So of course i made an iso of the cd figured it was a hardware thing but no this iso also upset the kernel to read files from, and they’d come out corrupt
I tried some iso tools from the debian cd and they seemed confused too
So i didnt know if my guix cd was bad, or debian was bad, or the laptop was bad. I checked the hash and signatures and the cd seemed good, which was quite slow to do in the old system without tools
So of course i strace’d the tools to figure out what logical offsets the data was at and began reverse engineering iso966- by inspection to see if i could make further progress, which i did, slowly
…
long story short it looks like the kernel on debian 12’s install cd has zisofs bugs, and i got to write an iso9660 decoder in my tmpfs mount that processed shared system use data and rockridge and zisofs zisofs is _poorly documented_ nowadays. It looks the official documentation is within a linux userspace tool repository now —